484 Dr. Meyer Wilderman on the Velocity of 



At equilibrium only the reaction in the homogeneous part 

 CaC0 3 ^Ca0 2 #. + C0 2 is to be considered, i. e., 



CIT -«_ 



where jo andjo/ are the vapour-pressure of the solid CaCO- ; 

 and CaO, p" is the pressure of C0 2 . We consequently get 



«"— ii?? — k 



P c'W ~~ ' 

 i.e.,p" is independent o£ the quantity CaC0 3 or CaO taken 

 (observations o£ Debray, 1867). If C0 2 be introduced we 

 liave 



(£) =< ^z cV(y " +A)=0 ' i,nd (/,,+A)= 7fe =K ' 



i, e., the pressure of C0 2 , which is ultimately obtained over 

 the solid CaCO ?) and CaO, will remain the same whether C0 2 

 is introduced or not (observations of Debray). 



For the velocity of decomposition of solid CaC0 3 into solid 

 CaO •+■ C0 2 , or of the formation of solid CaC0 3 from CaO 

 and C0 2 we have 



For CaC0 3 solid^- or -"-CaCOj gas : — 



the equation l-r) = c% r {po — J>t). 

 For CaC0 3 gas^CaO gas + CO a gas :— 



the equation (7-) = c t p T — c tt pr i pr r . 



For CaO gas-*" or -*-CaO solid : — 



dt \" 



the equation (-- \ =c ,/, S^ / (jOo , — pr) 



Now just as much of the solid CaC0 3 transforms in the unit 

 of time into gaseous CaC0 3 as gaseous CaO and C0 2 are 

 formed from gaseous CaC0 3 . Therefore 



__ cLtP q + <!' PtPt" 

 PT ~ C' + Clr' 



and 



( dt \- n y f n c2 r po+c"p T 'p r , ' \_ ^ ( p <--c"pr'pr" \ 



On the other hand we have that the number of molecules of 

 the solid CaO (if we neglect the quantity of the gaseous 

 CaO) which are formed in the unit of time is equal to the 



